code: def error(solution, prediction):
      # custom function defining error
      return np.mean(solution != prediction)
  
file_path: auto-sklearn/examples/40_advanced/example_metrics.py
imports: import numpy
  import sklearn.model_selection
  import sklearn.datasets
  import sklearn.metrics
  import autosklearn.classification
  import autosklearn.metrics
label_desc: Use image node_id 2 for calling a global function with example usage: error(solution, prediction) and returns: np